To identify a-gliadin peptides that are candidate sequences for celiac disease activating peptides. To verify that a-gliadin peptides which activate celiac disease have similar properties in vitro and in vivo. And to verify that peptides active in in vivo rectal model also activate celiac lesions in the small intestine. To define which amino acid residues within the a-gliadin peptides activate celiac disease and are necessary for activation of disease.